LED light sources in the prior art generally are encapsulated by using a fluorescent organic colloid. Such encapsulation manner makes the fluorescent powder tightly appressed to the LED chips. In the case of low power, there is no great problem. However, the two large-power heat sources will be superimposed on each other after the power density is increased, especially when an integrated encapsulation manner is used. This will lead to a rapid increase in the junction temperature of the LED chips, cause attenuation, aging or even carbonization of the fluorescent powder and the organic colloid, and result in reduction in the luminous efficiency and service life of the light source.
The specific composition of a current solid-state phosphor integrated light source includes a solid-state phosphor, a transparent organic silica gel, LED chips, a dam-encircling colloid and a substrate. The LED chips are arranged on the substrate, a dam-encircling colloid disposed on the substrate is arranged at the periphery of the LED chips, the solid-state phosphor is placed on the LED chips and fixed by the dam, the transparent organic silica gel is filled in the gap between the solid-state phosphor and the substrate. In this way, the transparent organic silica gel can be used to isolate the solid-state phosphor from the LED chips, so as to prevent the heat source of the solid-state phosphor from being directly superimposed on the heat source of the LED chips. However, it has been found in practice that the transparent fluorescent gel, being a poor conductor of heat, results in an insufficient heat conduction, thereby failing to reduce the temperature effectively and increase the service life.